Cartridge for explosives



Sept. 15, 1942.

M. F.. LINDSLEY, JR

CARTRIDGE FOR EXPLOSIVES Filed May 24, 1959 I gether.

Patented Sept. 15,1942

CARTRIDGE FOR EXPLOSIVE'S Milton F. Lindsley, Jr., Kings Mills, Ohio,assignor to The King Powder Company,

Kings Mills,

Ohio, a corporation of Ohio Application May 24, 1939, Serial No. 275,498

3 Claims.

This invention relates to cartridges for explosive compositions. Thecartridges are intended to be loaded with explosive and then loweredinto deep oil or gas wells. Detonation of the explosive in the cartridgeserves to relieve the congestion of the strata containing the oil orgas, and the explosion starts or increases the flow from the well.

In most cases, the wells are from four to eight inches in diameter; thedepth varies from several hundred to several thousand feet or more.Usually, the cartridges are lowered into the well until therequisite-charge has been placed in position. Detonation is causedeither by dropping a very sensitive high-explosive Jack-squib down thewell on the top column of explosive. or by equipping the uppermostcartridge of the column with an electrically detonatable blasting cap;

Up to the present time, well cartridges have been made of sheet metaland these have been loaded with powder at the well, or in the field.These operations are dangerous and time consuming, while the cartridgesthemselves are cumbersome and expensive.

An objective of this invention has been to provide cheap cartridgessuitable for the purpose, but-adapted particularly to be loaded at thepowder plant and shipped to the well ready for usage.

A further objective has been to provide unitary cartridges arranged tobe strung together, in chain fashion, to constitute a column ofexplosive suitable to be lowered intact into the well.

It has been another objective to provide a cartridge comprised primarilyof a paper container, yet sufliciently strong to withstand the tensionalstrain of the weight of the chain of loaded cartridges below it when itis being lowered into a well, and sulficiently strong to withstand thecompressional weight of a column of loaded cartridges above it when itis at the bottom of the well. These and other objectives are disclosedin the following specification and in the accompanying drawingwhichillustrates a preferred embodiment of the invention.

In the drawing:

Figure 1 is a perspective view of a cartridge of the invention. Thisview also illustrates the manner in which several cartridges are linkedto- Figure 2 is a cross-sectional view taken longitudinally of thecartridge.

Figure 3 i a top plan view.

Figured is. a view looking upwardly at the bottom of the cartridge.

Briefly, it is the concept of the present invention to combine apaperboard explosive container which is relatively strongcompressionally, with a lightweight cage made of steel straps which isrelatively strong tensionally. The paperboard container carrying theexplosive is carried within the cage, with the steel straps restingadjacent the walls of the container. Spiders are provided at each end ofthe cage adjacent the ends of the container, for keeping the straps ofthe cage in their predetermined positions,

Connecting rings or snap hooks are provided at each end of each cage, sothat the cartridges can be strung or linked together in chain form whena number of them are to be lowered simultaneously into a well. Duringthe lowering operation, the weight of the column is carried through theconnecting strap elements of the cages, so that there is no danger thatthe cartridges of the chain will break or separate. The strength of thepaperboard containers is sumciently great that they will not crush underthe weight load when the column is at the bottom of the well. Thestructure therefore provides cartridges which are very cheap toconstruct, and yet cartridges which are lighter in weight and much saferto handle and use than the cartridges which have been available in thepast.

- In the drawing, the paperboard container is indicated generally at I.This unit preferably is comprised of a paperboard tube having a lid 2and a cap 3; the tube preferably being spirally wound in theconventional manner. The lid 2 preferably is made of paper or the likeand fits over the tube. This lid is arranged for removal when the tubeis being loaded with explosive,

and, after the loading, the lid is sealed in posi- 7 tion either bymeans of a suitable adhesive or by means of a gummed tape wrapper 4.

The cap 3 preferablyis made of sheet metal in the form of a truncatedcone having a bottom platen5. The conical form of the cap is employed sothat it will serve to guide the cartridge as it is being lowered downthe bore hole of a well. In the preferred structure, the conical wall 6of the cap and the bottom plate 5 are joined together at a peripheralseam; this seam preferably extends below the surface of the plate so asto provide an annular flange l. A paperboard member 5a extends over thebottom plate 5 and serves to close the bottom of the cartridge. Thecentral portion of this member is offset inwardly as at 1a to permit thering, which is subsequently described, to clear it,

Referring to Figures 2 and 4, the plate 5 of the bottom cap contains acentral aperture 8 and a plurality of slot-like apertures 9' which arespaced annularly inwardly of the flange 1. Strap elements I0 and It arethreaded through the slots 9 and, therefore, the pairs of straps form abasket for the cap 3 constituting the bottom of the paper container. Thestraps H3 and I! may be threaded through diametrically opposed slots, tooverlap, as shown in the drawing, or

they may be threaded through adjacent slots, which are angulated inposition to receive the straps without distorting them, or in othersuitable manner.

The straps l and H preferably extend upwardly adjacent the interiorsurface of the cap 3, as shown in Figure 2, but exteriorly of the papercontaine At the upper end of cartridge, the straps are threaded throughslots I! which are spaced annularly in a spider member l3. This spideralso contains a central aperture I4 and has an upstanding marginalflange IS. The diameter of the cap inwardly of the flange l5 complementsthe diameter of the depending flange I. of the cap 3, so that the capsof adjacent cartridges can be nested together, if desirous. The strapsl0 and II can be threaded through opposed slots in the upper spider l3or may be threaded through adjacent slots appropriately angulated. It ispreferable that the straps be parallel to one another and to thelongitudinal axis of the cylinderfor even distribution of the load towhich they are subjected during the period when the cartridges are beingloaded in position.

A band [6 of adhesive tape or other suitable material is wrapped overthe straps around the paperboard container, so as to keep the strapslocated in their predetermined position.

In the preferred structure, the strap elements l0 and H comprise lengthsof strap metal appropriately clamped or clasped together as at l8, sothat they form loops which respectively embrace the sidesand ends of thecontainer, and which collectively constitute a cage for the container.One type of clamp suitable for this purpose is known as the Acme SteelStrap"; the details of such a clasp are shown particularly in Patent No.1,260,016 of March 19, 1918.

As shown in the drawing, the strap elements are divided into upper andlower mating portions of loops; the lower portions extend from pointsapproximately midway of the cartridges, down through the lower spiderslots of the cap 3, and up to approximately midway of the cartridge onthe other side; these strap portions are cornected by means of theclasps l8 to complementary strap portions depending from the upperspider. Thus, the one form of cage disclosed is comprised of a pair ofloops arranged at 90 from one another radially, each loop being-made upof an. upper portion and a lower portion joined together. The upper andlower strap portions are threaded easily and quickly through the slotsin the spiders and production of the cartridges in quantities issimplified. If desirous, the strap can be employed to interconnect thecaps alone, if modification of the structure is requisite or desirousfor constructing cartridges for particular purposes. A typical steelstrap'stretcher may be employed for bringing the straps into position,after which the straps may be joined as'by crimping, or other suitablefastening means.

For the purpose of interconnecting a plurality of the cartridges in theform of a chain, the rings l9 and are carried by the straps from thelower and upper ends of the cartridge respectively, with the respectiveapertures 8 providing clear- Each of these rings carries a ance forthem. snap hook or connector link 2|. By joining these snap hookstogether, as shown in Figure 1, the mdges readily are interconnectedtoform 9.

-- scope with one another as in the case of meta cartridges havingpointed ends.

Having described my invention, I claim: 1. A deep well cartridge forexplosives, comprising a paperboard tube, strap members for supportingthe tube, a truncated conical cap of sheet metal telescopically engagingthe tube at one end, the said strap members being arranged in the formof loops which are spaced apart and which extend around the end of thetube with which the said cap is associated, the saidcap 7 havingapertures therein, with the strap members being threaded through the capapertures so as to pass over the outside of the cap end and pass underthe side walls of the cap along the tube, whereby the cap holds thestraps in spaced relationship, the said strap members extending alongthe tube and over the other end thereof with the ends of the respectivestraps being interconnected to form continuous loops longitudinallyaround the tube, the said continuous loops cooperating to provide abasket by which the tube may be supported therefrom.

2. A deep well cartridge for explosives, comprising a paperboard tube,strap members which are spaced apart from one another and which extendlongitudinally around. the tube, a truncated conical cap of sheet metaltelescopically engaging the tube at one end, the said straps beingarranged in the form of loops and the said truncated cap havingapertures in its end wall, with the. straps being threaded through thecap apertures' so that the ends of the loops pass over the outside ofthe cap end and the portions of the straps adjacent the loop ends passunder the side walls of the cap and along the tube, whereby the capholds the straps in spaced relationship, another cap member extendingover the end of the tube at the end opposite the truncated cone andhaving strap receiving perforations, with the said straps passing alongthe wall of said tube and being threaded through said perforations tocross over said second cap exteriorally thereof, the strap means beingconnected to form continuous loops providing a basket through which thetube may be supported.

3. A deep well cartridge for explosives, comprising a paperboard tube,strap members forming loops which are spaced apart from one anotherradially 0f the tube, a truncated conical cap of sheet metaltelescopically arranged around the tube at one end, the said cap havingapertures therein with the straps being threaded through the capapertures so as to cross oneanother at the outside of the cap end andpass under the side walls of the cap end along the tube, whereby the capholds the straps in spaced relationship, the said straps passing alongthe tube and pas-sin: over the opposite end thereof and the ends of thestraps being interconnected to form on ous loops providing a basket bywhich the t be may be supported, and wrapper means exten 1; around thetube over the straps intermediate the ends of the tube.

MILTON F. LINDSLEY, JI-

